Tuning mechanism for drums



Feb. 20, 1962 w. F. LUDWIG 3,021,743

TUNING MECHANISM FOR DRUMS Filed Jan. 19, 1959 United States Patent iThis invention relates to tuning mechanisms for drums and, moreparticularly, is concerned with an improved kettle drum or tympaniconstruction wherein the tuning mechanism is arranged entirelyexternally of the kettle. In the prior art, most commercially produceddrums have utilized tuning mechanisms having their pull rods arrangedinternally of the kettle, and while it has been recognized that the manyopenings in the kettles re quired in this type of drum constructioninterfere with the instruments tone and that access to the enclosedmceahnism for lubricating the working parts is ditficult, if notimpossible, no satisfactory alternative construction has been availableheretofore.

Drums having external tuning mechanisms are known, but they haveemployed rather expensive and cumbersome constructions having exposedworking parts that are subject to damage when the instruments are movedaround in trunks.

The principal object of the present invention is to provide a drumconstruction having external pull rods that are protectively shieldedfrom mechanical damage while being readily accessible for lubricationand adjustment.

Another object is to provide an external actuating linkage for the pullrods that develops an increasing mechanical advantage as the headtension increases to provide security in holding the pitch in tuning.

Briefly, the invention employs an arrangement wherein the kettle issuspended from adjacent its upper end by a plurality of supportingstruts. The tensioning mechanism includes intermediate pull rodsarranged in shielded relation along the inside of each strut andconnected to suitable tuning levers mounted adjacent the upper end ofthe kettle, with intermediate bell crank levers being pivoted to thestruts and connected to external, generally radial pull rods that aresimultaneously controlled by a tuning mechanism mounted to a commonsupport for the struts.

A tuning mechanism of the counterbalanced foot pedal actuated type ispreferably employed to develop a balanced tuning action that tends tohold the pitch to which it is tuned. The effectiveness of this balancedaction is enhanced by the additional leverage afforded by the bell cranklevers inside the supporting struts.

Other objects and advantages will become apparent during the course ofthe following description.

-In the drawing, a kettle drum of tympanum constructed in accordancewith this invention is illustrated in side elevation, with parts thereofbroken away and sectioned for convenience of disclosure.

The drum includes a kettle preferably parabolic in form and made ofcopper or aluminum and base structure, generally designated at 11 andincluding a plurality of upstanding struts 12 supportingly connected tothe kettle adjacent its upper end. As is apparent from the drawing, thekettle is free of openings such as are commonly employed in drumarrangements using internal pull rods and is freely suspended fromadjacent its upper end by the supporting struts 12 for developing abetter tone.

As is conventional, the kettle is provided with a resonant drumhead 13and an anchoring hoop 14 that is in telescoping relation over the topend of the kettle for drawing the drumhead taut. The anchoring hoop isprovided with a plurality of bosses 14B at spaced points about ice itsouter periphery, with each boss being provided with a manually operableadjustment screw 15 for making initial adjustments in setting thetensioning of the drumhead. At their lower ends, the adjustment screwsare threadedly engaged in pins 16 that are rotatably carried in tuninglevers 1 7 which are suitably pivoted to the struts, as indicated at 18.These tuning levers are connected to and variably positioned by a noveltensioning linkage mechanism for selectively tuning the resonant head13, as will be made clear presently.

According to this invention, the tensioning linkage includes a commonconnection head 20 that is disposed beneath and vertically shiftablealong the axis of the kettle, a plurality of generally radiallyextending pull rods 21 each being pivotally anchored at one end to theconnection head and at the other end to an intermediate lever 22 in theform of a bell crank that is anchored to each supporting strut by asuitable pivot pin 22F, and a plurality of intermediate pull rods 23arranged to extend along the struts and each being pivotally anchored atits lower end to one of the bell cranks 22 and at its upper end to oneof the tuning levers 17.

For purposes of this disclosure, the connection head 20 of thetensioning linkage is shown in operative connection to a manuallyadjustable tuning mechanism of the counterbalanced pedal-actuated type,such as is shown in FIG. 3 of Ludwig et al. Patent 1,561,789. Forconvenience, the general organization and operation of the tuningmechanism is described briefly and, where possible, reference charactersidentical with the aforesaid patent are applied to corresponding parts.'In general, the tuning mechanism includes a main pull rod 37 that isanchored in the connection head 20 and shiftable along the axis of thekettle for varying the tension of the drumhead under the control of afoot pedal 30. The foot pedal carries adepending rock arm 31 operativelyconnected by a horizontal rod 32 and a bracket 46 to a pivotallyanchored reverse-motion member 33 which is in turn drivingly connectedto the main pull rod 37. The arrangement includes counterbalancingfacilities in the form of a compression spring 43 which acts upon theother end of the bracket 46 to develop a counterbalancing force thatallows the pedal 30 to remain at the particular position at which it isset even though the nautral tendency of the drumhead to contract appliesa restoring force to the tuning mechanism through the pull rods 23 and21 of the tensioning linkage.

In the drawing, the approximate low note and high note positions of theconnection head 20, pull rods 21, and foot pedal 30 are shown in fulllines and dotted lines, respectively.

One of the important advantages of the present arrangement resides inthe fact that the tensioning linkage employs the additional set of bellcrank levers 22 to provide increased leverage and thereby reduce theactuating force required for tensioning the drumhead. in addition, thesebell crank levers 22, as Well as the tuning levers 17, are arranged todevelop a mechanical advantage that increases as the tensioning on thedrumhead increases. In the drawing, the levers 17 and 22 are shown inthe position which they occupy when the drum is tuned to its low range,and as the tensioning is increased, the levers rotate in such a mannerthat their effective lever arms increase.

Probably the most important advantage of the drum arrangement of thisinvention is the fact that the tensioning linkages, while arrangedexternally of the kettle for reasons explained previously, arenevertheless effectively shielded from mechanical damage. It will benoted that the supporting struts 12 of this disclosure have the generalshape of a channel and define a protected guideway that opens inwardlytowards the kettle. The intermediate pull rods 23 are received withinthis guideway, while the bell crank levers 22 and tuning levers 17 arepivoted directly to the struts and disposed Within the guideWay, withsuitable tolerances being provided to accommodate all necessarymovements of these parts. Finally, the radial pull rods 21 are in anout-of-the-Way location beneath the kettle and thus require no directshielding. The struts themselves are rugged enough to Withstand shocksincident to moving these instruments about and, in any event, damage tothe strut Would not normally impair the operation of the tuningmechanism and tension-transmitting linkages. The invention has beendescribed in connection with a counterbalanced pedal-actuated type oftuning mechanism, and it Will be appreciated that the additionalleverage afiorded by the extra set of hell cranks alleviates thestresses which are set up when the drurnhead is under severe tension andthereby reduces the required effectiveness of the counterbalancing.Thus, the foot pedal action is better equalized.

Another advantage of the disclosed arrangement is the fact that thekettle is supported and contacted only at its upper end and is free ofopenings, and these kettle arrangements have been found to develop animproved tone It should be understood that the description of thepreferred form of the invention is for the purpose of com plying WithSection 112, Title 35, of the US. Code and that the claims should beconstrued as broadly as prior art will permit.

I claim:

1. In a drum, a kettle, a resonant head spanning the upper end of saidkettle, a plurality of means spaced circumferentially about said kettlefor tensioning said head on said kettle, base structure, manuallyadjustable means mounted to said base structure and including avertically shir'table connection head located beneath said kettle, aplurality of external struts secured to the base structure at pointsthereof spaced circumfercntially about and located lower than saidconnection head, said struts extending up- Wardly and supportinglyengaged to the kettle at points thereof spaced circumferentially aboutthe upper end thereof for suspending the kettle in spaced relation abovesaid base structure with said connection head disposed intermediatelytherebetween, and a plurality of mechanical linkages spaced externallyabout said kettle and individually associated with separate ones of saidstruts, each linkage extending between said connection head and aseparate one of said tensioning means to transmit motion therebetween,each linkage having means intermediately therealong engaged to thecorresponding strut to mount such linkage for movement about a fixedpoint located intermediately along the corresponding strut and there bymaintain the linkage spaced from contact with the kettle.

2. In a drum, a kettle having a resonant head and an anchoring hoop forthe head, =base structure, a manually adjustable tuning mechanism of thecounterbalanced foot pedal actuated type mounted to said base structureand. including a main tuning rod shiftable along a vertical axis passingthrough said base structure centrally thereof, said tuning rod carryinga connection head spaced beneath said kettle, a plurality of externalstruts secured to the r base structure at points thereof spaced aboutsaid axis and located lOWer than said connection head, said strutsextending upwardly to supportingly engage the kettle at points thereofspaced ci-rcumferentially about the upper end thereof, and ahead-tensioning mechanism including a plurality of tuning leverspivotally anchored adjacent said points about the upper end of saidkettle and having means connected to the anchoring hoop, a plurality ofintermediate levers pivoted to said struts intermediately therealong,intermediate pull rods extending along said struts and connecting saidintermediate levers to said tuning levers, and a plurality of generallyradial pull rods connecting said connection head to said intermediatelevers.

3. The arrangement of claim 2 wherein each of said struts is in theshape of a channel to define a guideway that receives and mechanicallyshields said intermediate pull rods, with said tuning levers beingdisposed on said struts for pivotal movement Within said guidewaysadjacent the upper end thereof and with said intermediate levers beingdisposed on said struts for pivotal movement Within said guideways, saidtuning levers and intermediate levers providing a mechanical advantagethat increases as the tensioning of the resonant head is increased bythe tuning mechanism.

References Cited in the file of this patent UNITED STATES PATENTS1,282,406 Gardner Oct. 22, 1918 1,561,789 Ludwig ct a1 Nov. 17, 19251,755,569 Strupe Apr. 22, 1930 2,074,194 Strupe Mar. 16, 1937

